diff options
author | Andy Wingo <wingo@pobox.com> | 2015-04-19 13:28:46 +0200 |
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committer | Andy Wingo <wingo@pobox.com> | 2015-04-19 13:32:26 +0200 |
commit | 2dd57213e1114c1e034e52b7ff8eaeaee752d9f3 (patch) | |
tree | 524803384d8065fd99a70fdbc1dff6ede6dce3f4 /src/resolve/resolved-dns-transaction.c | |
parent | 1dcca8e5fe679b21a7203d6e35d58aa7aa83bbe1 (diff) |
Remove src/resolve
Diffstat (limited to 'src/resolve/resolved-dns-transaction.c')
-rw-r--r-- | src/resolve/resolved-dns-transaction.c | 619 |
1 files changed, 0 insertions, 619 deletions
diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c deleted file mode 100644 index bc1a90db1b..0000000000 --- a/src/resolve/resolved-dns-transaction.c +++ /dev/null @@ -1,619 +0,0 @@ -/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ - -/*** - This file is part of systemd. - - Copyright 2014 Lennart Poettering - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. -***/ - -#include "af-list.h" - -#include "resolved-dns-transaction.h" - -DnsTransaction* dns_transaction_free(DnsTransaction *t) { - DnsQuery *q; - DnsZoneItem *i; - - if (!t) - return NULL; - - sd_event_source_unref(t->timeout_event_source); - - dns_question_unref(t->question); - dns_packet_unref(t->sent); - dns_packet_unref(t->received); - dns_answer_unref(t->cached); - - dns_stream_free(t->stream); - - if (t->scope) { - LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); - - if (t->id != 0) - hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); - } - - while ((q = set_steal_first(t->queries))) - set_remove(q->transactions, t); - set_free(t->queries); - - while ((i = set_steal_first(t->zone_items))) - i->probe_transaction = NULL; - set_free(t->zone_items); - - free(t); - return NULL; -} - -DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); - -void dns_transaction_gc(DnsTransaction *t) { - assert(t); - - if (t->block_gc > 0) - return; - - if (set_isempty(t->queries) && set_isempty(t->zone_items)) - dns_transaction_free(t); -} - -int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsQuestion *q) { - _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; - int r; - - assert(ret); - assert(s); - assert(q); - - r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); - if (r < 0) - return r; - - t = new0(DnsTransaction, 1); - if (!t) - return -ENOMEM; - - t->question = dns_question_ref(q); - - do - random_bytes(&t->id, sizeof(t->id)); - while (t->id == 0 || - hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(t->id))); - - r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); - if (r < 0) { - t->id = 0; - return r; - } - - LIST_PREPEND(transactions_by_scope, s->transactions, t); - t->scope = s; - - if (ret) - *ret = t; - - t = NULL; - - return 0; -} - -static void dns_transaction_stop(DnsTransaction *t) { - assert(t); - - t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); - t->stream = dns_stream_free(t->stream); -} - -static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { - _cleanup_free_ char *pretty = NULL; - DnsZoneItem *z; - - assert(t); - assert(p); - - if (manager_our_packet(t->scope->manager, p) != 0) - return; - - in_addr_to_string(p->family, &p->sender, &pretty); - - log_debug("Transaction on scope %s on %s/%s got tentative packet from %s", - dns_protocol_to_string(t->scope->protocol), - t->scope->link ? t->scope->link->name : "*", - t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), - pretty); - - /* RFC 4795, Section 4.1 says that the peer with the - * lexicographically smaller IP address loses */ - if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { - log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); - return; - } - - log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); - - t->block_gc++; - while ((z = set_first(t->zone_items))) { - /* First, make sure the zone item drops the reference - * to us */ - dns_zone_item_probe_stop(z); - - /* Secondly, report this as conflict, so that we might - * look for a different hostname */ - dns_zone_item_conflict(z); - } - t->block_gc--; - - dns_transaction_gc(t); -} - -void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { - DnsQuery *q; - DnsZoneItem *z; - Iterator i; - - assert(t); - assert(!IN_SET(state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); - - if (!IN_SET(t->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)) - return; - - /* Note that this call might invalidate the query. Callers - * should hence not attempt to access the query or transaction - * after calling this function. */ - - log_debug("Transaction on scope %s on %s/%s now complete with <%s>", - dns_protocol_to_string(t->scope->protocol), - t->scope->link ? t->scope->link->name : "*", - t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), - dns_transaction_state_to_string(state)); - - t->state = state; - - dns_transaction_stop(t); - - /* Notify all queries that are interested, but make sure the - * transaction isn't freed while we are still looking at it */ - t->block_gc++; - SET_FOREACH(q, t->queries, i) - dns_query_ready(q); - SET_FOREACH(z, t->zone_items, i) - dns_zone_item_ready(z); - t->block_gc--; - - dns_transaction_gc(t); -} - -static int on_stream_complete(DnsStream *s, int error) { - _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - DnsTransaction *t; - - assert(s); - assert(s->transaction); - - /* Copy the data we care about out of the stream before we - * destroy it. */ - t = s->transaction; - p = dns_packet_ref(s->read_packet); - - t->stream = dns_stream_free(t->stream); - - if (error != 0) { - dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); - return 0; - } - - if (dns_packet_validate_reply(p) <= 0) { - log_debug("Invalid LLMNR TCP packet."); - dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); - return 0; - } - - dns_scope_check_conflicts(t->scope, p); - - t->block_gc++; - dns_transaction_process_reply(t, p); - t->block_gc--; - - /* If the response wasn't useful, then complete the transition now */ - if (t->state == DNS_TRANSACTION_PENDING) - dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); - - return 0; -} - -static int dns_transaction_open_tcp(DnsTransaction *t) { - _cleanup_close_ int fd = -1; - int r; - - assert(t); - - if (t->stream) - return 0; - - if (t->scope->protocol == DNS_PROTOCOL_DNS) - fd = dns_scope_tcp_socket(t->scope, AF_UNSPEC, NULL, 53); - else if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { - - /* When we already received a query to this (but it was truncated), send to its sender address */ - if (t->received) - fd = dns_scope_tcp_socket(t->scope, t->received->family, &t->received->sender, t->received->sender_port); - else { - union in_addr_union address; - int family = AF_UNSPEC; - - /* Otherwise, try to talk to the owner of a - * the IP address, in case this is a reverse - * PTR lookup */ - r = dns_question_extract_reverse_address(t->question, &family, &address); - if (r < 0) - return r; - if (r == 0) - return -EINVAL; - - fd = dns_scope_tcp_socket(t->scope, family, &address, 5355); - } - } else - return -EAFNOSUPPORT; - - if (fd < 0) - return fd; - - r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); - if (r < 0) - return r; - - fd = -1; - - r = dns_stream_write_packet(t->stream, t->sent); - if (r < 0) { - t->stream = dns_stream_free(t->stream); - return r; - } - - t->received = dns_packet_unref(t->received); - t->stream->complete = on_stream_complete; - t->stream->transaction = t; - - /* The interface index is difficult to determine if we are - * connecting to the local host, hence fill this in right away - * instead of determining it from the socket */ - if (t->scope->link) - t->stream->ifindex = t->scope->link->ifindex; - - return 0; -} - -void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { - int r; - - assert(t); - assert(p); - assert(t->state == DNS_TRANSACTION_PENDING); - - /* Note that this call might invalidate the query. Callers - * should hence not attempt to access the query or transaction - * after calling this function. */ - - if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { - assert(t->scope->link); - - /* For LLMNR we will not accept any packets from other - * interfaces */ - - if (p->ifindex != t->scope->link->ifindex) - return; - - if (p->family != t->scope->family) - return; - - /* Tentative packets are not full responses but still - * useful for identifying uniqueness conflicts during - * probing. */ - if (DNS_PACKET_T(p)) { - dns_transaction_tentative(t, p); - return; - } - } - - if (t->scope->protocol == DNS_PROTOCOL_DNS) { - - /* For DNS we are fine with accepting packets on any - * interface, but the source IP address must be one of - * a valid DNS server */ - - if (!dns_scope_good_dns_server(t->scope, p->family, &p->sender)) - return; - - if (p->sender_port != 53) - return; - } - - if (t->received != p) { - dns_packet_unref(t->received); - t->received = dns_packet_ref(p); - } - - if (p->ipproto == IPPROTO_TCP) { - if (DNS_PACKET_TC(p)) { - /* Truncated via TCP? Somebody must be fucking with us */ - dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); - return; - } - - if (DNS_PACKET_ID(p) != t->id) { - /* Not the reply to our query? Somebody must be fucking with us */ - dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); - return; - } - } - - if (DNS_PACKET_TC(p)) { - /* Response was truncated, let's try again with good old TCP */ - r = dns_transaction_open_tcp(t); - if (r == -ESRCH) { - /* No servers found? Damn! */ - dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); - return; - } - if (r < 0) { - /* On LLMNR, if we cannot connect to the host, - * we immediately give up */ - if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { - dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); - return; - } - - /* On DNS, couldn't send? Try immediately again, with a new server */ - dns_scope_next_dns_server(t->scope); - - r = dns_transaction_go(t); - if (r < 0) { - dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); - return; - } - - return; - } - } - - /* Parse and update the cache */ - r = dns_packet_extract(p); - if (r < 0) { - dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); - return; - } - - /* According to RFC 4795, section 2.9. only the RRs from the answer section shall be cached */ - dns_cache_put(&t->scope->cache, p->question, DNS_PACKET_RCODE(p), p->answer, DNS_PACKET_ANCOUNT(p), 0, p->family, &p->sender); - - if (DNS_PACKET_RCODE(p) == DNS_RCODE_SUCCESS) - dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); - else - dns_transaction_complete(t, DNS_TRANSACTION_FAILURE); -} - -static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { - DnsTransaction *t = userdata; - int r; - - assert(s); - assert(t); - - /* Timeout reached? Try again, with a new server */ - dns_scope_next_dns_server(t->scope); - - r = dns_transaction_go(t); - if (r < 0) - dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); - - return 0; -} - -static int dns_transaction_make_packet(DnsTransaction *t) { - _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - unsigned n, added = 0; - int r; - - assert(t); - - if (t->sent) - return 0; - - r = dns_packet_new_query(&p, t->scope->protocol, 0); - if (r < 0) - return r; - - for (n = 0; n < t->question->n_keys; n++) { - r = dns_scope_good_key(t->scope, t->question->keys[n]); - if (r < 0) - return r; - if (r == 0) - continue; - - r = dns_packet_append_key(p, t->question->keys[n], NULL); - if (r < 0) - return r; - - added++; - } - - if (added <= 0) - return -EDOM; - - DNS_PACKET_HEADER(p)->qdcount = htobe16(added); - DNS_PACKET_HEADER(p)->id = t->id; - - t->sent = p; - p = NULL; - - return 0; -} - -int dns_transaction_go(DnsTransaction *t) { - bool had_stream; - int r; - - assert(t); - - had_stream = !!t->stream; - - dns_transaction_stop(t); - - log_debug("Excercising transaction on scope %s on %s/%s", - dns_protocol_to_string(t->scope->protocol), - t->scope->link ? t->scope->link->name : "*", - t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family)); - - if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { - dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); - return 0; - } - - if (t->scope->protocol == DNS_PROTOCOL_LLMNR && had_stream) { - /* If we already tried via a stream, then we don't - * retry on LLMNR. See RFC 4795, Section 2.7. */ - dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); - return 0; - } - - t->n_attempts++; - t->received = dns_packet_unref(t->received); - t->cached = dns_answer_unref(t->cached); - t->cached_rcode = 0; - - /* Check the cache, but only if this transaction is not used - * for probing or verifying a zone item. */ - if (set_isempty(t->zone_items)) { - - /* Before trying the cache, let's make sure we figured out a - * server to use. Should this cause a change of server this - * might flush the cache. */ - dns_scope_get_dns_server(t->scope); - - /* Let's then prune all outdated entries */ - dns_cache_prune(&t->scope->cache); - - r = dns_cache_lookup(&t->scope->cache, t->question, &t->cached_rcode, &t->cached); - if (r < 0) - return r; - if (r > 0) { - log_debug("Cache hit!"); - if (t->cached_rcode == DNS_RCODE_SUCCESS) - dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); - else - dns_transaction_complete(t, DNS_TRANSACTION_FAILURE); - return 0; - } - } - - if (t->scope->protocol == DNS_PROTOCOL_LLMNR && !t->initial_jitter) { - usec_t jitter; - - /* RFC 4795 Section 2.7 suggests all queries should be - * delayed by a random time from 0 to JITTER_INTERVAL. */ - - t->initial_jitter = true; - - random_bytes(&jitter, sizeof(jitter)); - jitter %= LLMNR_JITTER_INTERVAL_USEC; - - r = sd_event_add_time( - t->scope->manager->event, - &t->timeout_event_source, - clock_boottime_or_monotonic(), - now(clock_boottime_or_monotonic()) + jitter, - LLMNR_JITTER_INTERVAL_USEC, - on_transaction_timeout, t); - if (r < 0) - return r; - - t->n_attempts = 0; - t->state = DNS_TRANSACTION_PENDING; - - log_debug("Delaying LLMNR transaction for " USEC_FMT "us.", jitter); - return 0; - } - - log_debug("Cache miss!"); - - /* Otherwise, we need to ask the network */ - r = dns_transaction_make_packet(t); - if (r == -EDOM) { - /* Not the right request to make on this network? - * (i.e. an A request made on IPv6 or an AAAA request - * made on IPv4, on LLMNR or mDNS.) */ - dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); - return 0; - } - if (r < 0) - return r; - - if (t->scope->protocol == DNS_PROTOCOL_LLMNR && - (dns_question_endswith(t->question, "in-addr.arpa") > 0 || - dns_question_endswith(t->question, "ip6.arpa") > 0)) { - - /* RFC 4795, Section 2.4. says reverse lookups shall - * always be made via TCP on LLMNR */ - r = dns_transaction_open_tcp(t); - } else { - /* Try via UDP, and if that fails due to large size try via TCP */ - r = dns_scope_emit(t->scope, t->sent); - if (r == -EMSGSIZE) - r = dns_transaction_open_tcp(t); - } - if (r == -ESRCH) { - /* No servers to send this to? */ - dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); - return 0; - } - if (r < 0) { - if (t->scope->protocol != DNS_PROTOCOL_DNS) { - dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); - return 0; - } - - /* Couldn't send? Try immediately again, with a new server */ - dns_scope_next_dns_server(t->scope); - - return dns_transaction_go(t); - } - - r = sd_event_add_time( - t->scope->manager->event, - &t->timeout_event_source, - clock_boottime_or_monotonic(), - now(clock_boottime_or_monotonic()) + TRANSACTION_TIMEOUT_USEC(t->scope->protocol), 0, - on_transaction_timeout, t); - if (r < 0) - return r; - - t->state = DNS_TRANSACTION_PENDING; - return 1; -} - -static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { - [DNS_TRANSACTION_NULL] = "null", - [DNS_TRANSACTION_PENDING] = "pending", - [DNS_TRANSACTION_FAILURE] = "failure", - [DNS_TRANSACTION_SUCCESS] = "success", - [DNS_TRANSACTION_NO_SERVERS] = "no-servers", - [DNS_TRANSACTION_TIMEOUT] = "timeout", - [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", - [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", - [DNS_TRANSACTION_RESOURCES] = "resources", - [DNS_TRANSACTION_ABORTED] = "aborted", -}; -DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); |